Comparative study on the microbial corrosion resistance of mortars with Cu-Ti amorphous alloys and TiO2 nanoparticles

Concrete corrosion in wastewater pipelines is caused by biogenic sulfuric acid produced locally by sulfuroxidizing microorganisms. Concrete mixtures are commonly modified to prevent this form of corrosion by adding biocides to inhibit their biological activities. However, using biocides is not always desirable because of their limited lifespan and potential for leaching into the environment. Therefore, there is a need to develop more durable alternatives to prevent microbial-induced corrosion of concrete. In this study, three types of Cu-Ti amorphous alloys (Cu35Ti65, Cu50Ti50, and Cu65Ti35) were prepared by ball milling, and compared with commercially available TiO2 nanoparticles to assess their effects on the resistance of the microbial-induced corrosion performance of mortar. Detailed investigations were conducted on the appearance, mechanical properties, and corrosion depth of mortars at various exposure durations in an accelerated biocorrosion environment. The results revealed that the mortars mixed with Cu35Ti65, Cu50Ti50, Cu65Ti35, and TiO2 nanoparticles exhibited significantly better resistance to microbial-induced corrosion than the reference mortars. The resistance to microbial-induced corrosion of the mortar mixed with Cu50Ti50 was the best. The superior antimicrobial corrosion performance of the mortar containing Cu-Ti amorphous alloy is influenced by both smaller particle sizes and higher sterilization performance. These findings can contribute to the development of novel applications of amorphous alloys in functional concrete.